Ubuntu – Dual Monitor Configuration changes to “Mirrored” automatically

multiple-monitors

After installing 12.04 on my Samsung X120 Notebook (with Intel GMA 4500 internal graphics card) i have a Problem with the configuration off my 2nd monitor.

Its a 22" with 1680 * 1050 Pixel connected via HDMI.

I use the display configuration and set internal display=off and external display=main display. That works fine.
After rebooting i still have that configuration, but after a while (often when i press a button on the keyboard), the configuration automatically changes to "Mirror Screen" and the internal display switches on. Both displays then have a bad resolution.
When i do the manual display configuration again, everything is fine for the duration of that session.

What could be the problem, that this display configuration gets lost / resets?

Best Answer

I was having the very same problem, not just with 12.04 but with previous versions as well as mint, xubuntu and others.

I got so fed up I switched over to arch for the last 8 months or so, but when they switched over to systemd I had all sorts of problems and installed ubuntu again.

Problems started again. This time I noticed that if it was going to happen it would normally be soon after boot up. then I would reset it and it would be fine for the rest of the day.

Putting two and two together I had a look in cron.daily and ran each cron job separately. The apt job would crash X every time. There is also a apt-xapian-index job in cron.weekly that has the same effect.

So I just disabled the jobs (chmod -x) and the problems have stopped. Inside both of these scripts is a check to see if you are on ac power. If I run this X crashes, so I think the culprit is the on_ac_power command.

To see if you have the same problem open a shell and type on_ac_power. If you get a crash then you have the same problem as me.

Hopefully this will fix the issue for some people

Related Solutions

Ubuntu – Turn off laptop display and have monitor

Try installing arandr ,in your system as it gives you gui , which is easy to mange

enter image description here .

In the outputs tab you can easily turnoff your laptop's display (LVDS) and keep your monitor's one (VGA or in your scenario it might be HDMI1) as your primary display and save the layout. Add the following layout script into your startup menu, so when next time you login to your desktop it works without any extra inconvenience.

Ubuntu – Is this a dual monitor reset bug

I experienced a similar problem with Intel GM45 drivers. Everything seemed to be fine after logging in, but as soon as I pressed the "super/windows key" or starting any application, the screen changed to "mirror" mode. Setting it in the system settings or using xrandr to my desired setup made everything fine. It seems that after log in, the capabilities of the graphics card/monitor change. I don't know exactly the cause, but it might have something to do with the "samsung tools" I use. Anyway, letting the script

sleep 10
xrandr --output LVDS1 --auto --primary
xrandr --output VGA1 --auto --above LVDS1

run on startup made everything fine

Best Answer

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